Nearly six years later, as Romney tries for a second run for the presidency, his signature achievement as governor has become attack fodder for his rivals and a potential liability in a general election because of President Barack Obama's embrace of it as a model for his own health care law.

The two laws share the same DNA: requiring individual and employer mandates and subsidies, establishing health insurance exchanges, allowing young adults to stay on their parents' insurance and prohibiting insurers from denying people's claims based on pre-existing conditions.

Romney has said that his plan was only for the states and not for the national level. "Very early on, we were asked -- is what you've done in Massachusetts something you would have the entire government do, the federal government do? I said no, from the very beginning," the former governor said at a recent town hall in Ohio.

GIBSON: But Governor Romney's system has mandates in Massachusetts, although you backed away from mandates on a national basis.

ROMNEY: No, no, I like mandates. The mandates work.

FRED THOMPSON: I beg your pardon? I didn't know you were going to admit that. You like mandates.

ROMNEY: Let me -- let me -- oh, absolutely. Let me tell you what kind of mandates I like, Fred, which is this. If it weren't...

THOMPSON: The ones you come up with.

(LAUGHTER)

ROMNEY: Here's my view: If somebody -- if somebody can afford insurance and decides not to buy it, and then they get sick, they ought to pay their own way, as opposed to expect the government to pay their way.

ROMNEY: And that's an American principle. That's a principle of personal responsibility.

Later in the debate, Romney said that he wouldn't force other states to adopt the Massachusetts model, but reiterated his support for universal coverage.

A July 2009 USA Today op-ed -- published amid the often white-hot health care reform debate -- touted the "lessons we learned in Massachusetts," and in particular the individual mandate, as a model for Washington.

Romney has become testy about the question at times in interviews. To Fox News' Bret Baier in November 2011, he complained: "Bret, I don't know how many times I've said this, too. This is an unusual interview." He then laughed.

In an interview earlier in March with Megyn Kelly, Romney was asked about his "I like mandates" quote. "People have looked at this topic 100 times, more than 100 times, I have agreed that a state should be allowed, if it wants to, to have a health care mandate," he said. "Time and again I've pointed out I'm not in favor of a health care plan that included a national mandate."

Romney isn't the only Republican to have supported an individual mandate. In fact, his own rivals for the nomination have. Rick Santorum in the 1990s supported mandates as an alternative to Hillary Clinton's health care plan. Newt Gingirch also supported individual mandates as an alternative to the Clinton plan, but also well into his post-congressional career.

"They're the same f***ing bill. He [Romney] just can't have his cake and eat it too," Gruber said. "He can try to draw distinctions and stuff, but he's just lying. The only big difference is he didn't have to pay for his. Because the federal government paid for it. Where at the federal level, we have to pay for it, so we have to raise taxes."